The present application concerns a procedure for the reworking of an open-end spinning apparatus as well as a bearing arrangement for a spin rotor of an open end spinning apparatus. Open-end rotor spinning apparatuses for open-end spinning machines, for example, such as are made by the firm W. Schlafhorst AG and Co. and Rieter Ingolstadt Spinning Machine Construction AG, are generally comprised of a multiplicity of spinning elements as well as a plurality of apparatuses for the winding of the spun yarn. Such a spinning unit possesses a spin rotor, which, by means of a drive motor, is set into rotational motion. Of considerable importance in this matter is the manner in which the spin rotor is carried on its bearings.
The bearing assembly for the rotor shaft divides itself into a radial and an axial bearing system. In the case of the radial bearing, the spin rotor is set into a V-shaped notch between two support disks. The axial bearing arrangement, and the reaction to the axial force caused by the spin rotor which this generates during operation, is contained on a thrust bearing. Until a few years previously, the axial thrust bearing in the case of machines of the above described manufacturers, and thereby a substantial part of this type of spinning machines, was equipped with a ball on which the rotor shaft rested while turning. The necessary lubrication of this ball was carried out with the aid of an appropriate lubricant.
These types of axial bearing arrangements, however, have the disadvantage that, in order to enable the important rotation of the ball, special demands were called for in regard to the lubrication. In the majority of cases, for this reason, these balls were placed above an oil bath or an oil-containing medium for lubrication. Besides the continuous rotation of the ball, and therewith the danger of considerable abrasive wear, this kind of axial rotor bearing arrangement had the additional disadvantage that lubricant, because of the vibration and high RPM of the rotor shaft, migrated out of the bearing box and contaminated the spinning machine, i.e., the spinning apparatus. Because of the oily surfaces in the bearing area, it happened that fine dusts and fibers of the spinning process could agglomerate on the machine and encrust themselves. This buildup could then lead to disadvantages in the formation of yarn. Such waste material patches that loosened themselves could enter into the to-be-spun fiber material and cause subsequent contamination and non-uniformities in the product.
Moreover, these contaminating deposits had the disadvantage that a large maintenance expense continually accrued. Thus, at regular periods, a cleaning of the spinning machine as well as a monitoring of the lubrication supply of the axial bearing had to be done. Under these circumstances, it was often necessary to refill the lubricant containers, which increased the maintenance time even more.
In order to set aside the disadvantages of spinning machines with open-end spin rotors supported by bearings of this kind, the state of the technology developed a different approach to axial bearing systems. The arrangement of the bearings for the spin rotors was done without the ball and further allowed the removal of the lubrication, which contaminated the fibers. This type of bearing support has been made known by EP 0 435 016 A2.
Following the introduction of this type of pneumatically driven axial thrust bearing system, which avoided the above described disadvantages, attempts were made to substitute these modem bearing arrangements with simplified ball axial thrust bearings, where the construction of the bearing assembly was simple to the extent that an exchange of these two bearing systems could be carried out. For this required construction, the improved version of the pneumatic axial thrust bearing arrangement was used, and the ball axial thrust bearing was simply installed in the receiving enclosure of this modem pneumatic bearing. By this means, a version (minimized in size) of the known oil lubricated, ball axial thrust bearing assembly was pushed into the receiving housing for the modem pneumatic axial bearing system. Through this kind of retrofit of the bearing assembly with conventional systems, the desired advantages of the modem axial bearing methods were circumvented in order to substitute for them apparatuses which were constructed according to the older types of bearings. This kind of bearing design still, as demanded by its components, called for an oil-based lubrication. Instead of refitting the obsolete bearing system with modem pneumatic bearings, the state of the technology, contrary to this, surprisingly simply retrofitted the modem and improved bearing system with the old.
Thus, it is a principal object of the invention to allow many thousands of spinning apparatuses now in operation with an oil-media lubrication system of the rotor to be reworked without great cost by an appropriate procedure and an apparatus to execute the procedure. The reworking would permit the spinning apparatuses to meet the demands, which have been placed on spinning machines without the necessity of replacing the complete spinning apparatus or machine. The investment amounts for the modernization are held to a minimum and remain restricted to the necessary components. Additional objects and advantages of the invention will be set forth in part in the following description, or may be obvious from the description, or may be learned through practice of the invention.
The present purpose of the invention is solved by dismounting the bearing block from the open-end spinning apparatus, separating the axial bearing from the bearing block, and replacing it with an axial bearing carrier for an aerostatic axial bearing equipped with a matching surface on the bearing block. The reworking allows, in this operation, only a small expenditure of time and money in comparison to the substitution of new spinning machines or a new, modernized open-end spinning machine for machines containing the axial ball bearings.
Reworked open-end rotor spinning machines retain essentially the same advantages in regard to the character of the bearing assemblies as do newly purchased open-end rotor spinning machines already equipped with the recently installed pneumatic axial bearing system for the spin rotor. For the rework, essentially only the bearing block of the open-end rotor apparatus to be reworked needs to be dismantled, following which, in a simple manner, the axial bearing assembly found on the block can be separated, and, in accord with the invention, replaced with an axial pneumatic bearing carrying block.
The reworking can even be accelerated by, for example, doing the reworking section by section. The corresponding parts of the rotor bearing assembly on the open-end spinning machine can be removed and reworked in one section, while the other sections of the spinning machine remain in operation. In another advantageous method, already reworked bearing assemblies can be held on the ready, so that, upon the next removal of the original bearing, the new component can serve as an immediate replacement. Thus, only a very short break in production would occur. The now removed original bearing assemblies, can be reworked at an optional time and place, so that, subsequently, these reworked assemblies can be exchanged piece for piece for existing original bearing assemblies.
In an advantageous development of the invented procedure, the removal of the ball axial bearing assembly can be effected by machine cutting, for instance, by sawing or milling, or even by non-machine cutting such as by laser or by electron beam. In this way, a plane of separation, i.e., a separating surface, is generated quickly and advantageously, which can be immediately turned to rework operations. Preferably, this follows as an additional step in the procedure. Also, the plane surface is generated with a minimum of roughness depth, which advantageously serves as a matching surface for another complementary surface. Such a plane surface improves the fitting of the axial bearing block surface to the existing bearing block.
The separation of the ball axial bearing is carried out favorably in such a manner that the plane in which the separation occurred lies parallel to the plane in which the support disks lie, that is, that plane which is formed by the support disk pair proximal to the rotor, or the support disk pair proximal to the shaft end. Advantageously, the separation can be made between the two planes of the two above mentioned pairs of support disks. An advantageous separation line can be achieved by having the line in its course suddenly bend, and run perpendicular to the above described planes of the support disks.
The axial bearing carrier is advantageously designed with a corresponding matching surface, so that the separating surface is appropriate for the fitting of the axial bearing carrier onto the existing bearing block. This match is especially true, when the bearing block has been correspondingly machined. In a further advantageous development of the procedure, the separating surfaces are provided with fastening means for their union. In this way, the advantage is gained that the fastening of the axial bearing carrier is simple and quick, as well as being exact in surface match. In a particularly favorable option, the fastening means includes a boring, which preferably possesses an inner threading. Thereby, the fixing of the axial bearing carrier onto the existing bearing block is very simple, i.e., with threaded bolts.
By means of the invented bearing arrangement, an economical bearing has been constructed, the bearing block of which retains the advantages of the original bearing system of the spin rotor by means of support disks and at the same time inherently possesses the advantages of a pneumatic axial bearing of the spin rotor. For this purpose, the axial bearing carrier is equipped with a receptor for a bearing surface of a pneumatic axial bearing. By means of the construction of a matching surface, no further measures are required for the installation of the bearing surface of the axial bearing to the spin rotor, at least that call for a change of the angularity of the bearing surface in relation to the axis of the rotor shaft.
In a particularly advantageous development of the bearings, the separating and the matching surfaces are simultaneously shaped, so that they, in connection with the axial bearing carrier, assure that no adjustments are necessary which alter the placement of the bearing surface in the axial direction of the spin rotor. This is particularly favorable, since no time for such adjustment can be lost and, moreover, no special knowledge is required of the maintenance personnel. The separation surface is machined for this reason in accord with the invention. The separation surface forms a centering and positioning surface of the bearing plate of the axial bearing for the rotor shaft, which will be rotationally carried thereon.
In a particularly advantageous improvement of the invention, the separation surface is provided with fastening means with the help of which the fastening of the bearing carrier is simple and advantageous. In a particularly advantageous development of the invention, this fastening means is a boring provided with a thread. In a further advantageous improvement of the invention, the separation surface possesses a centering means for the centering, or alignment, of the bearing carrier onto the existing bearing block. For example, these centering means might be centering pins, or complementary borings for the same. By these alignment means, a rapid and sure centering of the bearing carrier on the existing bearing block can be carried out during the installation. These alignment means simplify the mounting and accelerate the installation of the bearing components and thereupon the rework of the open-end rotor spin apparatus.